Tyre breaker made of separate parallelogram-shaped sections



March 13, 1962 D, D'OYLY COOPER 3,024,829

TYRE BREAKER MADE OF SEPARATE PARALLELOGRAM-SHAPED SECTIONS Filed Aug. 29, 1958 rO/a MM @4 7 4 1 United States Patent 3,024,829 TYRE BREAKER MADE OF SEPARATE PARALLEL- lGRAM-SHAPED SECTEONS David Henry DOyly Cooper, Acocks Green, Birmingham, England, assignor to Dunlap Rubber (Iompany Limited, London, England, a British company Filed Aug. 29, 1958, Ser. No. 758,122 Claims priority, application Great Britain Sept. 24, 1957 14 Claims. ((31. 152--361) This invention relates to pneumatic tyres.

According to the invention a reinforcement for the tread region of a pneumatic tyre cover comprises a plurality of substantially parallelogram-shaped sections of tyre-building fabric incorporating a plurality of parallel filaments or cords, the sections being disposed to form an endless band with the filaments or cords of the sections substantially uniformly distributed around the band, each section being interleaved between two adjacent sections with a portion of each section overlying one of the adjacent sections and another portion underlying the other adjacent section.

Substantially one-half of each section may overlie one of the adjacent sections, the remaining half underlying the other adjacent section, the overlying and underlying halves being either substantially triangularor trapezoidal-shaped.

The angular disposition of the filaments or cords in alternate sections is preferably the same as and of opposite sense to the angular disposition of the filaments or cords in the remaining sections.

Preferably the filaments or cords in each substantially parallelogram-shaped section are rectilinear but they may each be inclined at a different angle along a part or parts of its length compared with the remainder of its length or they may each be curved.

The sections may be arranged in three or more tiers, each section being interleaved between adjacent sections and extending for a portion of its length in each tier.

In an alternative construction the angular disposition of the filaments or cords in alternate sections is the same as but of different numerical value from that of the filaments or cords in the remaining sections.

In a yet further construction the central portion of each section overlies or underlies the central portion of the middle of three adjacent sections while each of the end portions of each section respectively underlies or overlies an end portion of one of the outer of the three adjacent sections.

The invention also includes pneumatic tyre covers incorporating tread reinforcements of the above-mentioned kind.

According to the invention also a method of manufacturing a reinforcement for the tread region of a pneumatic tyre cover comprises assembling a plurality of sub stantially parallelogram-shaped sections of tyre-building fabric, each incorporating a plurality of parallel filaments or cords, in overlapping relationship one with the other to form an endless band with the filaments or cords of the sections substantially uniformly distributed around the hand.

More particularly, according to the invention, the method comprises overlapping the substantially parallelogram-shaped sections so that each section is interleaved between two adjacent sections, the filaments or cords in each section being of opposite bias angle to those of the adjacent sections, substantially one-half of each section lying above one of the adjacent sections and the remain ing portion lying below the other adjacent section, the overlying and the underlying halves each being either substantially triangularor trapezoidal-shaped.

3,024,829 Patented Mar. 13, 1962 According to the invention also a penurnatic tyre is provided incorporating a reinforcement manufactured according to the above method.

The tyre-building fabric is preferably rubberized and may be of weftless or woven, e.g., square woven, construction. The material of the filaments or cords may be steel, a textile material, e.g., cotton or rayon, a synthetic material, either in monofilamentary or staple form, e.g., nylon or polyethylene terephthalate which may be, for example, Terylene (the word Terylene is a registered trademark). Where the tyre-building fabric is of woven construction different materials, such as those referred to, may be used for the warp and the weft. If heatshrinkable materials such as nylon or "Terylene (the word Terylene is a registered trademark) are used in woven constructions, the shrinkage of the material, when subjected to temperatures such as are used for moulding pneumatic tyre covers, results in a compact breaker construction, the shrinkage being of assistance in obtaining resistance to deformation under transverse forces (e.g. cornering force) applied to a tyre incorporating the breaker.

Reinforcement bands in accordance with the invention can be used alone or in conjunction with a conventional breaker or breakers, for example, a strip of rubberized weftless steel cord fabric, having the cords disposed at to the mid-circumferential line of the cover carrying the breaker. The band or the bands and breaker or breakers may be mounted on a carcass reinforced with material having filaments or cords disposed at, e.g., about 45 or 90, the filaments or cords being of any suitable material e.g. textile material or steel.

The invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIGURE 1 shows a diagrammatic plan view of a basket-weave breaker band in fiat form with the parallelogram-shaped sections displaced sideways with respect to each other from their normal position in which the sides of all the sections are in alignment.

FIGURE 2 is a similar view to that shown in FIGURE 1 of an alternative construction.

FIGURE 3 is a cross-sectional view taken along the line 3-3 shown both in FIGURES 1 and 2.

FIGURE 4 is a cross-sectional view taken along the line 4-4 shown both in FIGURES 1 and 2.

FIGURE 5 shows a diagrammatic perspective view of a further alternative construction in flat band form with the parallelogram-shaped sections in alignment.

FIGURE 6 shows a diagrammatic end view of the construction shown in FIGURE 5 with the band in annular form.

FIGURE 7 shows a similar view to that shown in FIGURE 1 of a further alternative construction.

FIGURE 8 shows a diagrammatic developed planview of a further alternative construction with the parallelogram-shaped sections in alignment. The band is of endless interwoven form and is integral at the chaindotted lines.

A reinforcement band, diagrammatically shown in FIGURES 1, 3 and 4, is constructed by cutting 6 exactly similar parallelogram-shaped sections 11 from a length of weftless fabric incorporating rubberized steel cords 12, each of the sections having steel cords running parallel with one pair (13a and 13b) of opposite sides. The perpendicular distance between the second pair (14a and 14b) of opposite sides is equal to the width of the finished band. The ratio of the length of a side of the first pair to that of a side of the second pair is made such that a line 15 drawn from the point of intersection of the two sides 13a and 14b and passing at right angles through 3 the other side 14a, divides the side 14a into two equal arts.

P The six sections are then assembled in overlapping and interleaving relationship one with another to form an endless band in the following manner. A first section A is laid upon the surface of a table and a second section B is laid upon the first so that the opposite sides 14a and 14b of section B are parallel to and coextensive with the sides 14a and 14b of section A, the cords of section B crossing those of section A. A third section C is laid upon the section B in a similar manner, the cords in section C crossing those in section B. Sections D, E and F are assembled as described in connection with the sections A, B and C to form a single band. The section F is then brought into overlapping relationship with the section A so as to form an endless band.

The band thus formed is made up of sections comprising cords which pass from one side of the band to the other, and, in a preferred construction are disposed at an angle of 18 to the mid-circumferential line of the endless band, substantially all of the cords of each section passing from the outer surface of the band under an overlapping section to the inner surface thereof. The cords n the outer surface of the band cross those on the inner surface. Substantially one half of each section lies above one of the adjacent sections and the remaining half lies below the other adjacent section, the overlying and the underlying halves each being triangular in shape. The 'cords 13a and 13b at the adjacent edges of any alternate pair of sections lie closely parallel to each other but are separated by the cords of the intervening section. Thus the cords are substantially uniformly distributed around the band, there being, at any cross-section of the band, two parallel sets of cords spaced at substantially equal intervals in each set. The cross-sectional views shown in FIGURES 3 and 4 illustrate the fact, that substantially throughout the band, the parallelogram sections pass from the upper surface to the lower surface of the band (FIG- URE 3) while, at isolated positions, the band consists of one section above another (FIGURE 4).

The band may then be located around the periphery of a tyre carcass; previously constructed and partially shaped 'to assume U-shaped cross-section, the construction of the tyre cover being completed in the usual manner and the the assembled cover moulded and vulcanized.

The construction shown in FIGURE 1 with the cords in the sections disposed at 18 to the mid-circumferential plane of the endless band may be assembled on a tyre carcass in the tread region together with a conventional breaker layer of parallel steel cordsdisposed at 90 to the said plane.

-Inan alternative method of manufacturing the reinforcement band, the band is assembled, after the manner described, directly around the periphery of a tyre carcass.

Any even number of parallelogram-shaped sections may be utilized to form a band in accordance with the invention the number utilized depending on the angle of the cords required in thefinished band, its width and its length.

FIGURE Z illustrates an alternative construction in which the ratio of the length of a side of one pair of sides to that of a side of the second pair of sides is not, in contrast to the construction shown in FIGURE 1, critical.

In the construction of FIGURE 2, the six parallelogram-shaped sections are again exactly similar and made from a length of weftless fabric incorporating rubberized steel cords running parallel to the opposite pair of sides 16a and 161). They are assembled in similar manner to that which is described in connection'with FIGURE 1 with the exception that in the finished band trapezoidalshaped, instead of triangular-shaped halves of each section are disposed one half above an adjacent section and the other half below the other adjacent section. The cords 16a and l6b'at the adjacent edges .ofany alternate 4, pair of sections lie closely parallel to each other but ar separated by th cords of an intervening section.

In the construction in FIGURE 5, each parallelogramshaped section is of the kind used in the construction of FIGURES 1 and 2 but of greater length in proportion to its width, and is disposed in four tiers. Each section, when the band is joined end-to-end is overlaid, for a part of its length by one, then by two, then by three other sections. For instance, section P is first overlaid by section Q. It is then overlaid by sections Q and R and then by sections Q, R and S. This can be seen in both FIG- URE 5 and FIGURE 6. It will be noted that in the portions of the sections overlaid by other sections the arrangement is such that the angular disposition of cords in overlying portions is opposite to that of the portions which are overlaid.

FIGURE 7 illustrates a further arrangement which is made up from parallelogram-shaped sections of two different kinds. The parallelogram-shaped sections 17 are of the kind utilized in the construction illustrated in FIG- URE 2 and the parallelogram-shaped sections 18 are of similar kind but composed of parallel cords disposed at to their longitudinal sides 18a. The two types of sec tions are assembled in turn, one half of each section (say of the first type 17) lying above an adjacent section of the other type (18) and the other half of the section lying below the other adjacent section also of type 18.

In a yet further construction shown in FIGURE 8, each parallelogram-shaped section is of the kind used in the constructions of FIGURES l and 2 but of greater Width 1n proportion to its length. Sections a a a and 41 are of the same bias angle but of opposite sense to that of sections b b b and b,,. The sections are assembled so that each section is interleaved between three adjacent sections instead of between two as in the case with the constructions of FIGURES 1 and 2. For instance, the central portion of section a overlies the central portion of section b while one end of section a underlies section 12 and the other end of it underlies section [2 on the other band, the central portion of section b underlies the central portion of section 0 while one end of section b;., overlies section a and the other end of it overlies section 2.

Reinforcement bands in accordance with the invention may be constructed with the cords in the finished band disposed at any angle required with the cords lying parallel to either one or the other of the opposed pairs of sides of th parallelograms.

With a conventional tread reinforcement there is some residual cornering force, i.e., cornering force when the tyre is running in a straight line direction, which appears to be due to the fact that the radially outermost reinforcement layer has cords at a particular bias angle With respect to the circumferential plane of the tyre. An advantage of the tread reinforcements according to the invention is that there is substantially no residual cornering force since the angular disposition of the cords on the radially outermost surface of the reinforcement changes several times around the complete circumference of the tyre as a result of the interweaving of parallelogram-shaped sections.

Similar constructions to the constructions shown in FIGURES 1, 2, 3 and 4 may be made by a different method which is disclosed in the copending application of Smith and Wright, Ser. No. 761,680, filed September 24-, 1957, now abandoned.

Having now described my invention, what I claim is:

1. A reinforcement for the tread region of a pneumatic tyre cover comprising a plurality of separate parallelogram-shaped sections of tyre building fabric incorporating a plurality of parallel filaments, the sections being disposed to form an endless band with the filaments of the sections substantially uniformly distributed around the band, each section being interleaved between two adjacent sections with a portion of each section overlying one of the adjacent sections and another portion underlying the other adjacent section.

2. A reinforcement according to claim 1 wherein the angular disposition of the filaments in alternat sections is the same as and of opposite sense to the angular disposition of the filaments in the remaining sections.

3. A reinforcement according to claim 2 wherein substantially one half of each section overlies one of the adjacent sections and the remaining half underlies the other adjacent section, the overlying and the underlying halves each being substantially triangular-shaped.

4. A reinforcement according to claim 3 with the modification that the overlying and the underlying halves are each substantially trapezoidal-shaped.

5. A reinforcement for the tread region of a pneumatic tyre cover comprising a plurality of separate parallelogram-shaped sections of tyre building fabric incorporating a plurality of parallel filaments, the sections being disposed in at least three tiers to form an endless band and each section being interleaved between adjacent sections and extending for a portion of its length in each tier, the angular disposition of the filaments in alternate sections being the same as and of opposite sense to that of the cords or filaments in the remaining sections.

6. A reinforcement for the tread region of a pneumatic tyre cover comprising a plurality of separate parallelogram-shaped sections of tyre building fabric incorporating a plurality of parallel filaments, the sections being disposed to form an endless band and each section being interleaved between two adjacent sections with a portion of each section overlying one of the adjacent sections and the remaining portion underlying the other adjacent section and the angular disposition of the filaments in alternate sections being the same as but of different numerical value from that of the filaments in the remaining sections.

7. A reinforcement for the tread region of a pneumatic tyre cover comprising a plurality of separate parallelogram-shaped sections of tyre building fabric incorporating a plurality of parallel filaments, the sections being disposed to form a continuous band and each section being interleaved between three adjacent sections, the filaments in each section having the same bias angle as but of opposite sense to that of the three adjacent sections, and each section having the two outer of the three adjacent sections passing on the same side thereof while the middle of the three adjacent sections passes on the other side thereof.

8. A reinforcement as claimed in claim 2 in which the sections incorporate steel wire filaments.

9. A reinforcement as claimed in claim 2 in which the sections incorporate woven fabric.

10. A pneumatic tyre cover incorporating in the tread region a reinforcement comprising a plurality of separate parallelogram-shaped sections of tyre building fabric incorporating a plurality of parallel filaments, the sections being disposed to form an endless band with the filaments of the sections substantially uniformly distributed around the band, each section being interleaved between two adjacent sections with a portion of each section overlying one of the adjacent sections and another portion underlying the other adjacent section.

11. A pneumatic tyre cover according to claim 10 incorporating in the tread region an additional reinforcement comprising a layer of steel wire filaments disposed at to the mid-circumferential plane of the tyre.

12. A method of manufacturing a reinforcement for the tread region of a pneumatic tyre cover comprising assembling a plurality of separate parallelogram-shaped sections of tyre-building fabric, each incorporating a plurality of parallel filaments, in overlapping relationship one with the other to form an endless band with the filaments of the sections substantially uniformly distributed around the band.

13. A method according to claim 12 wherein the parallelogram-shaped sections are assembled to overlap so that each section is interleaved between two adjacent sections, the filaments in each section being of opposite bias angle to those of the adjacent sections, substantially one half of each section lying above one of the adjacent sections, the remaining half lying below the other adjacent section and the overlying and the underlying halves each being substantially triangular-shaped.

14. A method according to claim 13 wherein the parallelogram-shaped sections are assembled to overlap so that each section is interleaved between two adjacent sections, the filaments in each section being of opposite bias angle to those of the adjacent sections, substantially one half of each section lying above one of the adjacent sections, the remaining portion lying below the other adjacent section and the overlying and the underlying halves each being substantially trapezoidal-shaped.

References Cited in the file of this patent UNITED STATES PATENTS 1,294,330 Carlisle Feb. 11, 1919 1,345,994 Carlisle July 6, 1920 1,734,241 Wikle Nov. 5, 1929 2,501,644 Kraft et al Mar. 21, 1950 2,703,132 Darrow Mar. 1, 1955 FOREIGN PATENTS 771,570 Great Britain Apr. 3, 1957 780,765 Great Britain Aug. 7, 1957 

